In shallow baking dish or plastic bag, pour 1/4 cup dressing; add chicken, turning to coat evenly. Cover; refrigerate 2 hours. Grill or broil chicken 6 minutes on each side or until done; cool and cut into chunks. Cook pasta according to package directions. Rinse with cold water to cool quickly; drain well. In large bowl, stir together chicken, cooled pasta, tomatoes, green pepper and broccoli. Toss lightly with remaining dressing. Cover; refrigerate before serving.